In order to control and maintain an air-conditioned space at a specific air-conditioning environment a technology that uses a distributed system flow analysis technique for estimating thermal distributions and an airflow distributions within a space has been proposed as a technique for determining operating volumes such as flow rates, flow directions, temperatures, and the like of conditioned air that is supplied from air-conditioning equipment. See, for example, Japanese Unexamined Patent Application Publication 2011-089677.
In this air-conditioning controlling technology, first forward analysis of the state of air-conditioning in the air-conditioned space is performed using a distributed system flow analysis techniques, the distribution data indicating the distribution of temperatures and air flows within the air-conditioned space are calculated, and then, based on setting data wherein target temperatures are applied to specific locations within the air-conditioned space in the distribution data that is obtained, reverse analysis is performed on the temperature and airflow distributions within the air-conditioned space using distributed system flow analysis technique to back-calculate new operating volumes indicating new blowing speeds and blowing temperatures for the air-conditioned space from the blowing vents, required to cause a specific location to go to a target temperature.
The use of the forward analysis in the conventional distributed system flow analysis technique, described above, makes it possible to estimate the air-conditioning environment that would be produced through air-conditioning control of the air-conditioned space using operating volumes for the various hypothetical operating volumes. Consequently, it is possible to estimate, in advance, as solutions for achieving various air-conditioning environments, combinations of the air-conditioning environments and the operating volumes obtained, enabling the selection of any given solution from these solutions, to control an air-conditioning system based on the operating volumes included in the solution, to achieve any given air-conditioning environment easily.
On the other hand, when actually performing air-conditioning control, there are multiple objectives for the air-conditioning control, such as the operating policies of the administrators who control the air-conditioned space, and the desires of the users who use the air-conditioned space. With such objectives, there are objectives that have mutual trade-off relationships. For example, while typically the objectives for air-conditioning control include energy conservation and comfort, these have a trade-off relationship.
Because of this, if a solution for use in air-conditioning control is selected from solutions that have been estimated in advance, it is important to extract the Pareto solutions (the optimal solutions) as solutions that consider the trade-offs between such objectives. A Pareto solution is a solution wherein, in order to improve the value of one objective function it is necessary to adversely affect the value of one or more other objective functions, that is, it is a compromise solution. Specifically, a Pareto solution is a solution that provides a better evaluation than other solutions under specific conditions.
FIG. 5 is an explanatory diagram illustrating Pareto solutions. Here two objectives for air-conditioning control having a trade-off relationship, specifically energy conservation and comfort, are selected, and based on the respective evaluation values wherein the objective functions for evaluating these objectives are calculated and symbols for various solutions, including the Pareto solution, are plotted at coordinate locations corresponding to the evaluation values, on a display screen. As illustrated in FIG. 5, a Pareto solution is a solution wherein, if an achievement level for one, namely energy conservation (or comfort) is selected, air-conditioning control is achieved that maximizes the achievement level of the other, namely comfort (or energy conservation) while satisfying the achievement level for energy conservation (or comfort). Consequently, a Pareto solution can be understood to be a solution that takes into consideration the balance between these objectives.
If one of the Pareto solutions is selected in this way from among the plurality of Pareto solutions that indicate the operating volumes for controlling the air-conditioning environment and the operating volumes for that Pareto solution are provided to the air-conditioning system, then it will be possible to perform air-conditioning control taking into account balance among a plurality of objectives regarding air-conditioning control, such as the operating policies by the administrators and the desires of the users, and the like.
However, normally for a given air-conditioning environment there is a plurality of operating volumes for controlling and maintaining the air-conditioned space in the desired air-conditioning environment. For example, if the temperature of a specific location within the air-conditioned space is to be reduced to a target temperature, there may be a method wherein the blowing speed of the air-conditioned air that is blown in from a blowing vent that exists near that location is increased, along with a method wherein the blowing temperature of the air-conditioned air that is blown in from that blowing vent is reduced instead.
Consequently, even for Pareto solutions that are close for the achievement levels for energy conservation and comfort, there will be cases wherein there are large differences between the operating volumes indicated by the respective Pareto solutions.
Moreover, if there are large differences in the operating volumes, then transitioning from the original operating volumes to the new operating volumes may require some time. For example, for the blowing temperature it is necessary to adjust the heat exchange in the air-conditioning equipment, producing a time delay depending on the time constant of the heat exchange. Moreover, even after controlling to the new blowing speed and blowing temperature, still there will be the time delay until changing to the new air-conditioning environment due to the time constants of the air distribution and heat distribution in the air-conditioned space. Because of this, when there are large differences in operating volumes it is not possible to transition the air-conditioning environment smoothly and efficiently. Moreover, such large differences in the operating volumes are also factors that contribute apprehension by the users of the air-conditioned space.
The present invention is to solve such problems, and an aspect thereof is to provide an air-conditioning controlling technology wherein it is possible to transition an air-conditioning environment, without producing apprehension, smoothly in accordance with objectives for the air-conditioning control, based on individual Pareto solutions for achieving a given air-conditioning environment.